# 2025-02-06-ui-buffer-caching-optimization

## Changes Made

### Commit 1: 79a972a - Fix GuiDropdownBox behavior with static edit mode variables
- Fixed 7 dropdown controls that were incorrectly sharing edit mode variables
- Each dropdown now has its own static `editMode` variable
- Affected controls: orbit type, body/craft selection, burn direction, trigger type
- Updated maneuver dialog progress documentation

### Commit 2: b37497a - Implement UIState buffer caching to eliminate per-frame malloc/free calls
- Implemented comprehensive buffer caching system in UIState
- Cached 4 buffer types:
  - Body names list (for object selection dropdown)
  - Spacecraft names list (for object selection dropdown)
  - Maneuver names list (for maneuver info display)
  - Maneuver status strings list
- Added `needs_update` flags for each cached buffer
- Added `last_counts` to track when buffers need invalidation
- Eliminated all per-frame malloc/free calls in ui_render_info_panel_objects()
- Eliminated all per-frame malloc/free calls in ui_render_info_panel_selected()
- Integrated cache invalidation into main loop and maneuver execution

### Commit 3: 028b8a8 - Fix UI buffer caching: remove dead code, use count-based invalidation, fix update bug
- Removed dead code from simulation.cpp/h (52 lines removed, 16 lines from header)
- Simplified invalidation logic: removed `buffer_valid` flag in favor of count-based checks
- Fixed bug where maneuver status cache was not being updated after maneuver execution
- Separated concerns: ui_renderer handles UI cache, simulation module no longer has UI code

### Commit 4: c76380f - Fix UI: maneuver status updates, ZII initialization, helper functions for cache checks
- Fixed maneuver status update bug: status strings now properly update after execution
- Fixed ZII initialization in ui_render_info_panel_selected: all state variables now use `= {0}`
- Added helper functions:
  - `check_needs_update_simcount()` - checks if cache needs update based on body count
  - `check_needs_update_craftcount()` - checks if cache needs update based on craft count
  - `check_needs_update_maneuvercount()` - checks if cache needs update based on maneuver count
- Refactored buffer update logic to use helper functions for clarity
- Updated AGENTS.md with command reference for testing

## Results

**Net line count changes:**
- Insertions: 322
- Deletions: 179
- **Net: +143 lines**

## Functionality Implemented

### Buffer Caching System
- Dynamic array allocation only when counts change
- Automatic cache invalidation based on body/craft/maneuver counts
- Helper functions for count-based cache invalidation checks
- Integration points:
  - `main_loop()` - invalidates caches before rendering
  - `execute_maneuver()` - invalidates maneuver cache after execution

### UI Improvements
- Fixed all dropdown controls with static edit mode variables
- Proper separation of concerns between UI and simulation modules
- Cleaner, more maintainable cache update logic

### Code Quality
- ZII (Zero Is Initialization) pattern applied to UIState
- Removed 52 lines of dead code from simulation module
- Better code organization with helper functions